PUBLIC LANDS:

A package of bills to expand hunting, fishing and shooting opportunities on public lands will have a key test vote this evening in the Senate, offering another chance for a gridlocked upper chamber to pass popular legislation affecting the environment.

But while S. 2363, the "Bipartisan Sportsmen's Act," carries 45 co-sponsors and is backed by a bevy of sportsmen's and conservation groups spanning the political spectrum, many fear it could fall victim to the same partisan fights over amendments that have derailed bipartisan bills this year to boost energy efficiency and extend energy tax breaks.

As the 2014 midterm election inches closer, proponents of the sportsmen's bill say the window of opportunity for Senate passage is quickly closing.

"This represents absolutely the best chance this Senate has," said Steve Kline, a lobbyist for the Theodore Roosevelt Conservation Partnership, a key backer of the sportsmen's bill. "If this thing slips past the August recess, I think it gets further mired in election-year politics."

But Kline emphasized that the bill has the votes to pass on its own merits.

The Senate tonight will be voting on limiting debate on the motion to proceed to the bill, a procedural hurdle that requires 60 votes to overcome.

The proposal by Sens. Kay Hagan (D-N.C.) and Lisa Murkowski (R-Alaska) was billed as a bipartisan breakthrough when it was first introduced in February. Both sides had previously introduced their own sportsmen's packages.

Its 12 provisions include measures to reauthorize programs that conserve wetlands for waterfowl and allow federal agencies to use revenues from land sales to acquire lands of higher conservation value.

One provision would devote a certain portion of land conservation funding to acquire tracts or easements to increase access to federal lands for hunting, angling and other recreation.

Another key provision would require the Bureau of Land Management and Forest Service to ensure they are promoting hunting, angling and target shooting on public lands, a mandate that many sportsmen argue is lacking in those agencies' core statutes.

More than half of the package's sponsors are Republicans.

The Congressional Budget Office has not "scored" the legislation, or estimated its cost.

Senate leaders have also yet to indicate an agreement on what amendments may be offered.

Bill proponents fear Republicans will seek votes on controversial amendments to overturn Obama administration policies to expand the reach of the Clean Water Act or to require power plants to cut emissions of global warming gases, or to approve the Keystone XL pipeline.

Past impasses over amendments led to the death of a popular energy efficiency bill by Sens. Jeanne Shaheen (D-N.H.) and Rob Portman (R-Ohio) and of a package to renew dozens of expired tax breaks, including key incentives for renewable energy, biofuels and efficiency.

Some senators may also explore an amendment to approve a bill by Sens. Ron Wyden (D-Ore.) and Mike Crapo (R-Idaho) to overhaul how the nation pays to fight wildfires. The proposal -- backed strongly by sportsmen's and conservation groups and included in President Obama's fiscal 2015 budget request -- is designed to safeguard money the Forest Service uses for non-fire programs including timber management, which can affect the quality of habitat for big game and fish.

While the wildfire provision carries bipartisan support, particularly in the West, any vote to approve an Obama environmental initiative in an election year would spark some controversy. Some budget hawks have opposed the wildfire proposal, seeing it as a gateway to increased federal spending.

The sportsmen's package will also face fierce resistance from certain environmental and animal rights groups that have long opposed the bill's provisions to clarify that U.S. EPA may not regulate lead in ammunition or fishing tackle under the Toxic Substances Control Act and to allow hunters to import a few dozen polar bear carcasses they shot outside the United States before the bears were federally protected.

The Center for Biological Diversity will be waging "a creative and aggressive public education campaign" in multiple states in opposition of both the lead ammo and polar bear provisions, said Bill Snape, a senior attorney for the group. He said CBD's campaign will include North Carolina, where Hagan faces a tough re-election bid.

CBD argues lead ammunition is a threat to birds and humans, and the provision is also opposed by many other bird advocacy groups and the Natural Resources Defense Council.

The Humane Society of the United States recently issued an action alert to followers calling S. 2363 "a devious bill that combines several radical hunting proposals into one package."

"In a single swoop, this legislation would open millions of acres of public lands -- including sensitive Wilderness Areas -- to hunting and fur trapping, at the expense of other land users and endangered and threatened species," the group said, urging followers to contact their members of Congress.

Hunting is already allowed in the vast majority of wilderness areas on BLM and Forest Service lands, as long as states allow it.

One major unknown is whether influential Democrats will oppose the bill's lead ammo or polar bear provisions.

Environment and Public Works Chairwoman Barbara Boxer (D-Calif.) actively fought passage of a previous sportsmen's package by Sen. Jon Tester (D-Mont.) in late 2012 over the same lead ammunition provision. An email to Boxer's office was not returned last week.

Conservative-leaning sportsmen's and gun rights groups in the past have signaled that they would oppose the removal of the lead provision.

Susan Recce, director of conservation, wildlife and natural resources at the National Rifle Association, a group that wields particular influence among Republicans, in 2012 said the absence of the lead language in Tester's package would have been a "deal breaker."

Melissa Simpson, director of government affairs at Safari Club International, said the group "looks forward to [the Hagan-Murkowski bill's] passage," but she did not respond to whether the lead provision was a crucial component.

A fact sheet released by the National Shooting Sports Foundation touts the importance of the lead provision in the Hagan-Murkowski package, saying a lead ammo ban as proposed by CBD would "devastate hunting and shooting sports participation," increase ammunition costs and reduce conservation dollars raised by hunters.

Influential sportsmen's groups say lead ammunition is not a threat to wildlife populations, but many hunters also say non-lead bullets are a responsible and affordable alternative.

Tester's sportsmen's package ultimately died after Republicans raised a budget point of order over a provision aimed at raising the cost of duck hunting permits. The Senate then ran out of time during its lame-duck session.

The duck hunting provision is not in the Hagan-Murkowski package, even though it carries strong support from key sportsmen's groups and the Obama administration.